Optical projection apparatus.



J. W. HENWOOD.

OPTICAL PROJECTION APPARATUS.

APPLIOATION FILED APR;26, 1910.

Patented Nov. 15,1910.

4 SHEETS-SHEET 1.

J. W. HENWOOD OPTICAL PROJECTION APPARATUS.

APPLICATION FILED APILZS, 1910.

Patented Nov. 15, 1910.

4 SHEETS-SHEET 2.

J. W. HENWOOD. OPTICAL PROJECTION APPARATUS.

APPLICATION TILED APILZB, 1910. 975,949. Patented Nov. 15, 1910.

4 SHEETSSHEET 3.

W Jwa J. W. HENWOOD.

OPTICAL PROJECTION APPARATUS.

APPLICATION FILED APR. 26, 1910. 4 975,949, Patented Nov. 15, 1910.

4 SHEETS-SHEET 4.

JOHN WILLIAM HENWQOD, OF LONDON, ENGI AND.

OPTICAL PROJECTION .AiPPAIRMA'I.US.

Specification pf Letters Patent.

Patented Nov. 15, 1910.

A Application filed April 26, 1910. Serial N0. 557,713.

To all whom 'it may concern:

Be it known that I, JOHN WILLIAM HEN- woon, a subject ofthe King of England, residing at London, England, have invented certam new and useful Improvements in Optical Projection Apparatus, of which the following is a specification.

The present invention relates to optical projection apparatus adapted to enable indications to be more readily visible to an observer who may be at a distance from any inst'rument'embodying this invention.

This invention relates more particularly to optical projection apparatus for showing at any moment the speed of a motor or other vehicle or the speed of rotation of en ines or shafting but is not limited in its app ication in this respect.

The present inverrtionconsistsqfan op:

' tical projection apparatus having in combination a source of light, a screen with a face presented away from said source, a light .projector which is directed toward said face and is situated in the path of rays derived from said source, an optical magnifying device and light flexing devices disposed in the path of the rays proceeding from said source to said light pro ector.

I will describe my invention in combination with an electro-ma netic s eed indicator of the type describe in British Patent No. 11817 /l895' issued to Albert Campbell.

The invention will be more readily understood from the following description taken in conjunction with the accompanying drawings which illustrate several constructions of apparatus embodying the features of this invention.

Figure 1 is a vertical sectional view, partly in elevation, of an apparatus embodying my invention; Fig. 2 is a similar View of a modified construction. Fig.3 is a similar view of a furthermodification. Fig. 4 is a similar view of still another modification. Figs. 5 and 6 are detail views illustrating an alarm device and Fig. 7 is a' detail view illustrating an inductor.

Like-letters indicate like the drawings.

C indicate vibratile fingers, which in practice are arranged in the form of groups. These fingers are each fixed at one end to the ring B and placed side by side so as to parts throughout stand up in the circumference of a circle, in such a manner that although thelr lengths Vary considerably, their upper or free ends are all at the same level. The top ends are made thin and broader than the other portions of the fingers which are individually of the same width andthickness throughout each group, except where fixed to the ring B.

The fingers may be arranged in any number of groups and any one group may comprise any number of fingers those in each group being of the same thickness, except those for the lowest speeds which may be' made thinner as necessary. This arrangement greatly increases the range and utility of the instrument.

Secured-to the base A are supports A. to which are attached the electromagnets D of which any convenient number may be used. The coils of these electromagnets may be connected in series or parallel. The pole faces D are of arcuate form of such radius that each is approximately concentric with the fingers. Eachfinger is provided with a small projection C opposite the pole piece D to strengthen and concentrate the pull of the electromagnet. A casing E fits on to the base A. This casing surrounds the working parts of the speed indicator to pro; tect them from damage and prevent the entry-of dust.

A scale F which, in practice, would be circular and having a series of numbers on it is supported by brackets F. The fingers are provided with ends which are hookshaped or bent at right angles to the length of the fingers, such finger ends or bent portions being given a curve which corresponds to the arc of vibration. Theseends are arranged to overlap the numbers on the scale F when the fingers are stationary or vibrate but slightly; but when any one finger vibrates considerably its end moves clear of a number thus indicating clearly the speed of the moving part whose revolutions or reciprocations 1t 1s desired to note. A cover G is provided with a flange G which fits 1 over the casing E. In the center of the 1nstrument an electric incandescent lampI is placed so that its divergent rays are picked up by an annular glass reflector J, carried by brackets J and employed to divert out ground glass screen K.

when stationary, immediately above this scale and above the finger ends a number of lenses H are disposed, so as to project an enlarged image of the number disclosed by a vibrating finger, on to the ring-shaped Fig. Zillustrates a preferred form of optical projection apparatus, also provided with a single projection-apparatus and a screen by means of which the-indications of the instrument may be magnified and made visible at a distance. The arrangement of the vibratile fingers and electro-magnets is similar to that described in connection withscale F supported by brackets F. The

. cover [G an when the cover is put on. A threaded ring hook-shaped ends of the fingers-overlap this scale and above them a series of lenses I-I, carried in brackets H, are placed. At an angle to and above the lenses an annular concave reflector-N is situated. In the cen ter of the instrument, mounted on the casing L, is a magnifying reflector O the reflecting surface of which is according to this invention presented away from instead of tloward the'source oflight, 2'. e. the lamp and directlyabove this reflector in the center of the cover G, a ground glass screen K is I placed and is held in position by means ofthe screwed ring G. The reflector O is in the form ofa convex plate. The reflector N is held tightly in position by'means of a num-' berof sprin s G which are, attached to the which press on the reflector L holds both the reflector O and lamp base I in positionwhen it is screwed on to the, casing L. 3 A

'Fig's. 3and4il1ustrate types of optical proj ection apparatus for indicating between very wide ranges ofs eed, each of which is provided with a mu tiple projection-apparatus anda screen.- In Fig. 3 two rows of vibratile fingers C 0*, are shown with the electromagnets for operating them. A source of light. is rovlded located so that the rays are reflecte on to both of two annular concave reflectors M M*. *Fromthese reflectors rays are reflected through the translucent scales F 'F*, and above these scales two rows of lenses H 'H* are placed to projectthe numher disclosed by the vibratingfinglqer on to the ground glass screens K i 4 is somewhat like Fig. 3 but is provide wit two annular concave reflectors. N N* at"- ranged so that the number projected on to both of them from both of the translucent scales H H* is projected on to the convex reflector O in the center of the instrument and from there reflected magnified fto the ground glass screen K placed in'the center of the cover G above themeflector 0.

Figs. 5 and 6 show an alarm device where by a signal may be given when and during the time'that a-,,certain speed is being exceeded.. This device consists of a metal piece P concentric with the fingers. To each end of this metalpiece is attached, but insulated therefrom, a flexible strip of metal P. Across the top of these strips is placed a strip of. metal P so dispose that when a selected finger or one out of a selected group of fingers'is vibrated, contact is made with the bar I and the circuit for ringing the electric bell is completed. 1

Fig. 7 illustrates an inductor Q carried by the shaft R whose revolutions are to be counted. This inductor is provided with a number of projections Q and is rotated close to the end of the permanent magnet S. The coils S of the magnet are joined in series or parallel with the coils ofthe magnets D of the speed indicator and the magnetic impulses'produced in the coils S by the projections on the inductor as it rotates close to the-ends of the permanent magnet S,cause similar impulses in the magnets D with the result that the finger whose natural vibration period corresponds to the number of magnetic impulses received from the inductor, will vibrate an disclose the number corresponding to the speed of the moving part.

The number of teeth on theiinductor and its speed of rotation are arranged to correspond to or to be proportional to the speed of the part whose velocity is to be indicated and to the number of vibrations required for the finger allotted to that particular'speed.

What I claim. as my invention and desire to secure by Letters Patent is 1. In an apparatus of the-character described, the combination with ascale plate having difl'ering indicesthereon, and means -for covering and uncovering said indices, of

asource" of light, a receiving surface, and

means arranged to cause rays of light from said source to pass through the scale plate and project theindices as they areuncovcred upon said'receiving surface.

2. In an apparatus of the character described, the combination. with a scale plate having diflering in'dices thereon, and means for covering and uncovering said indices, of

a source .of light, a receiving surface, and

means to cause raysof light from said source to .pass through the, scale plate and project an enlarged image of each indication as it 1s uncovered upon sald receiving surface.

In an apparatus of the character de.-. scribed, the combination with a scale late having difieringindices arranged circ arly thereon, and means for covering and uncovg ering said indices, of a source of light arranged centrally with respect to the said indices, a receiving surface, and means for causing rays of light from said source to pass through the scale plate and project the indices as they are uncovered upon said receiving plate.

4.-'In an apparatus of the character described, the combination with a scale plate having differing indices thereon, and means for coverin and uncovering said indices, of a source 0 light, a receivlng surface, and

reflecting and refracting bodies arranged to them to pass through the scale plate and project the indices as they are uncovered upon said receiving surface, enlarged as set forth.

6. In optical projection-apparatus, the combination of a source of light, a reflector having its reflecting face presented away from said source, a light-flexing device which encircles an axis passing through the source and is presented toward said source, a second light-flexing device which is presented toward the first and toward the aforesaid reflector, optical ray-diverging devices situated in. the path of the rays derived from said source, optical ray-converging devices also situated in the path of the sald rays, and a translucent image-receiving screen presented toward the aforesaid reflector, and a scale late having differing indices thereon and throu h which scale plate pass the rays of light from the first-mentioned light-flexing device.

7. In optical projection apparatus, the combination of a source of light, a reflector having its reflecting face presented away from said source, a light-flexing device which encircles an axis passing through the source and is presented toward said source, a second light-flexing device which is resented toward the first and toward the a oresaid reflector, optical ray-diverging devices situated in the path of the. rays derived from said source and optical ray-converging devices also situated in the path of the said rays, a scale plate havin differing indices thereon and through whlch scale plate 'pass the rays of light from the first-mentioned light-flexing device, and an imagereceiving screen to receive the image reflected from the aforesaid reflector.

8. In optical projection apparatus, the combination of a source of light, a reflector having its reflecting face presented away from, said source, a lightflexing device which encircles an axis passing through the source and is presented toward said source,

a second light-flexing device which is presented toward the first and toward the aforesaid reflector, and optical ray-diverging devices situated in the path of the rays derived from said source, a scale plate having differing indices thereon and through'which scale plate pass the rays of light from the first-mentioned light-flexing device, and an image-receiving screen to receive the image reflected from the aforesaid reflector.

9. In optical projection apparatus the combination of a source of light, a reflector with its reflecting face presented away from said source, a light-flexin device which encircles an axis passing trough the source and is presented toward said source and a second ight-flexing device which is presented toward the first and toward the screen, a scale plate having differing indices thereon and through which scale plate pass the rays of 1i ht rom the first-mentioned lightflexing twice, and an image-receiving screen to receive the image reflected from the aforesaid Y reflector.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JOHN WILLIAM HENl/VOOD. Witnesses:

WILLIAM JOHN TENNANT, HARRYB. BRIDGE. 

